U.S. Pat. No. 3,155,273, issued May 31, 1963, to R. A. Cote, and U.S. Pat. No. 4,200,200, issued Apr. 29, 1980, to Carl C. Hein, III, and Joseph J. Spitz, disclose cartons for stacks of interfolded tissues. In each instance, the top of the carton has an opening for access to the interior, but the opening is closed by a film having a longitudinal slit. The slit forms a "valve" having abutting or nearly abutting, somewhat flexible lips. A single tissue projecting through the lips may be pulled for removal from the box. Ideally, the next lower tissue is drawn through the valve and retained in a position partially projected from the box. However, in this type of construction, the next lower tissue is not always reliably drawn through the valve or held projecting from it. In that case, the user must insert his or her fingers downward through the valve for access to the next tissue. This procedure is inconvenient, particularly for those with limited dexterity or painful ailments of the fingers or their joints.
Patents on containers seeking to address this problem include the following: U.S. Pat. No. 3,012,692, issued Dec. 12, 1961, to B. B. Petersen; U.S. Pat. No. 4,623,074, issued Nov. 18, 1986, to Donald D. Dearwester; U.S. Pat. No. 4,944,405, issued Jul. 31, 1990, to John C. Buford and Leslie H. Porter; and U.S. Pat. No. 5,540,354, issued Jul. 30, 1996, to Charles A. Annand. In each instance, a container is provided with a side opening for access to stacked tissues. Nevertheless, the valved box having only a top opening continues to be a commonly used container, with the problem noted above.